Table 2 Multivariate Meta-Regression analysis of colistin resistance among Gram-Negative Bacteria in Egypt

Preselected resistant phenotypes for colistin susceptibility testing (Reference = total recovered isolates)

 Carbapenem resistance

9.8

3.9

15.7

0.001

**

 Multi-drug resistance

5.7

− 1.9

13.4

0.14

Region (Ref: Greater Cairo)

 Delta Region

0.5

− 4.4

5.4

0.83

 Upper Egypt

9.3

0.5

1.8

0.04

.*

Susceptibility method, Reference = Broth Microdilution

 Agar diffusion-based susceptibility testing methods (E-test and Disc Diffusion Methods)

− 3.0

-9.2

3.2

0.35

 VITEK 2 system

-7.0

-13

-1.0

0.02

*

Study Period: 2012–2022

 Year

1.8

0.7

2.8

0.001

**